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Please Note: The author retains the copyright while the New Jersey Institute of Technology reserves the right to distribute this thesis or dissertation Printing note: If you do not wish to print this page, then select “Pages from: first page # to: last page #” on the print dialog screen The Van Houten library has removed some of the personal information and all signatures from the approval page and biographical sketches of theses and dissertations in order to protect the identity of NJIT graduates and faculty. ABSTRACT SIMULATION, PERFORMANCE AND INTERFERENCE ANALYSIS OF MULTI-USER VISIBLE LIGHT COMMUNICATION SYSTEMS by Adel Aldalbahi The emergence of new physical media such as optical wireless, and the ability to aggregate these new media with legacy networks motivate the study of heterogeneous network performance, especially with respect to the design of protocols to best exploit the characteristics of each medium. This study considers Visible Light Communications (VLC), which is expected to coexist with legacy and future radio frequency (RF) media. While most of the research on VLC has been done on optimizing the physical medium, research on higher network layers is only beginning to gain attention, requiring new analyses and tools for performance analysis. The first part of the dissertation concerns with developing a new ns3-based VLC module that can be used to study VLC-RF heterogeneous networks via simulation. The proposed ns3 module is developed based on existing models for intensity modulated LED signals operating as lighting units transmitting to optical receivers at indoor scales (meters). These models and the corresponding simulation model are validated using a testbed implemented with a software-defined radio (SDR) system, photodetector, phosphor-converted “white” LEDs, and under PSK and QAM modulation. Two scenarios are used in the validation of the VLC module: (i) using a receiver placed right bellow the transmitter with varying range, and (ii) using a receiver with a fixed range and varying angle of acceptance. Results indicate good correspondence between the simulated and actual testbed performance. Subsequently, it demonstrates how the VLC module can be used to predict the performance of a hybrid WiFi/VLC network simulated using the ns3 environment with UDP, TCP, and combined network traffic. The second part of the dissertation focuses on modeling interference at VLC system level based on variable pulse position modulation (VPPM) and variable on-off keying (VOOK) which are used in VLC to simultaneously provide lighting with dimming control as well as communication. The bit error performance of these modulation schemes is evaluated at VLC systems consisting of multiple transmitters-receivers pairs, where co- channels interference exists. The BER is derived by providing an in depth analysis that captures the signal structure of the interference in terms of the number of transmitters. This work dispenses with the Gaussian interference model which is not suitable when the number of interferers are few and the central limit theorem (CLT) cannot be applied. The result shows that under realistic small-room scenario, the analytical results closely match with that of simulation. SIMULATION, PERFORMANCE AND INTERFERENCE ANALYSIS OF MULTI-USER VISIBLE LIGHT COMMUNICATION SYSTEMS by Adel Aldalbahi Advisor: Abdallah Khreishah A Dissertation Submitted to the Faculty of New Jersey Institute of Technology in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Electrical Engineering Helen and John C. Hartmann Department of Electrical and Computer Engineering December 2017 Copyright c 2017 by Adel Aldalbahi ALL RIGHTS RESERVED APPROVAL PAGE SIMULATION, PERFORMANCE AND INTERFERENCE ANALYSIS OF MULTI-USER VISIBLE LIGHT COMMUNICATION SYSTEMS Adel Aldalbahi Dr.AbdallahKhreishah,DissertationAdvisor Date Associate Professor of Electrical and Computer Engineering, NJIT Dr. Nirwan Ansari, Committee Member Date Distinguished Professor of Electrical and Computer Engineering, NJIT Dr. Mengchu Zhou , Committee Member Date Distinguished Professor of Electrical and Computer Engineering, NJIT Dr.Sui-HoiEdwinHou,CommitteeMember Date Professor of Electrical and Computer Engineering, NJIT Dr. Moussa Ayyash, Committee Member Date Professor of Information Sciences, Chicago State University BIOGRAPHICAL SKETCH Author: Adel Aldalbahi Degree: Doctor of Philosophy Date: December 2017 Undergraduate and Graduate Education: • Doctor of Philosophy in Electrical Engineering, New Jersey Institute of Technology, Newark, NJ, 2017 • Master of Science in Power and Energy Systems, New Jersey Institute of Technology, Newark, NJ, 2013 • Bachelor of Science in Electrical Engineering, Virginia Commonwealth University, Richmond, VA, 2011 Major: Electrical Engineering Presentations and Publications: Adel Aldalbahi, Michael Rahaim, Abdallah Khreishah, Moussa Ayyash, Thomas D. C. Little, “Visible Light Communication Module: An Open Source Extension to the ns3 Network Simulator With Real System Validation,” IEEE Access, Vol, 5, 22144 - 22158, 2017. Adel Aldalbahi, Michael Rahaim, Abdallah Khreishah, Moussa Ayyash, Ryan Ackerman, James Basuino, Walter Berreta and Thomas D.C. Little, “Extending ns3 to simulate visible light communication at network-level,” 23rd International Conference on Telecommunications. Adel Aldalbahi, Abdallah Khreishah and Moussa Ayyash, “Modeling and Analysis of Interference in Multi-user Visible Light Communication Systems based VPPM scheme,” under preparation. Adel Aldalbahi, Abdallah Khreishah and Moussa Ayyash, “Modeling and Analysis of Interference in Multi-user Visible Light Communication Systems based VOOK scheme,” under preparation. iv v ACKNOWLEDGMENT First of all, I thank Allah for the good health and all his blessings that were necessary to complete this dissertation. Second of all, I would like to express my great appreciation to my advisor, Dr. Abdallah Khreishah who has been a wonderful guide to me and for his patience in the last four years. I would like to thank him for his support throughout my doctoral studies and for allowing me to grow as a researcher. Your advice, support and valuable comments have been priceless. My gratitude also extended to my committee members, Dr. Nirwan Ansari, Dr. Mengchu Zhou, Dr. Sui-Hoi Edwin Hou and Dr. Moussa Ayyash for honoring me as members of my dissertation committee. I also want to thank them for their priceless comments and suggestions on this dissertation. I would also like to thank Dr. Michael Rahaim and Dr. Thomas DC Little for their valuable feedback. My gratitude also due to my lab-mates Hazim Shakhatreh, Sihua Shao and Dr. Ammar Gharaibeh for the unlimited discussions I had with them. Finally, I thank my parents, my brothers, my sisters, my wife and my daughter for their support throughout this journey and encourage me to reach my goal. vi TABLE OF CONTENTS Chapter Page 1 INTRODUCTION ................................ 1 1.1 History of Optical Communication Systems ................ 4 1.1.1 Recent Optical Wireless Communication Systems ......... 6 1.1.2 Research Motivation ........................ 8 2 RELATED WORK ................................ 10 3 EXTENDING NS3 TO SIMULATE VISIBLE LIGHT COMMUNICATION AT NETWORK-LEVEL ........................... 15 3.1 Introduction ................................ 15 3.2 NS3 Conceptual Overview ......................... 17 3.3 Analytical Modeling of VLC Channel ................... 19 3.3.1 VLC Channel Model ........................ 20 3.3.2 VLC Performance Model ...................... 21 3.4 Design Requirements and Principles .................... 23 3.4.1 VLC Helper Classes ........................ 23 3.4.2 VLC Channel Class ........................ 24 3.4.3 VLC Error Model Classes ..................... 25 3.4.4 VLC Mobility Class ........................ 26 3.5 Combining VLC into ns3 ......................... 26 3.6 Simulator Experiment ........................... 26 3.6.1 Simulation Settings ........................ 27 3.6.2 Simulation Results ......................... 28 4 VISIBLE LIGHT COMMUNICATION MODULE:AN OPEN SOURCE EXTENSION TO THE NS3 NETWORK SIMULATOR WITH REAL SYSTEM VALIDATION 33 4.1 Introduction ................................ 33 4.2 Theoretical Design of VLC Channel .................... 36 vii TABLE OF CONTENTS (Continued) Chapter Page 4.2.1 Channel Model ........................... 37 4.2.2 Performance Analysis of VLC ................... 38 4.3 ns3-VLC Module .............................. 43 4.3.1 VLC Net Device .......................... 44 4.3.2 VLC TX Net Device ........................ 45 4.3.3 VLC RX Net Device ........................ 46 4.3.4 VLC Mobility Model ........................ 47 4.3.5 VLC Error Model